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BAD STUMBLE OFF IDLE UNDER LOAD


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2000 v11 28,000 miles will not move smoothly from stop, have to rev it up before taking off so it wont 

stumble and or die. Have done the tune up no help. Only does this when hot, if I unplug the heat

sensor it runs great. So I am thinking a possible CPU problem going to lean when hot?

Thanks in advance all ideas appreciated.

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It's the sensor. Why would you chose the ECU ( the expensive bit) over the cheap less reliable component?

As the engine warms up the trim reduces to zero at 90 deg C and then goes negative the hotter it gets after that. I think if you disconnect the sensor the ecu goes to a default temp setting. 

 

Phil

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1 minute ago, thumper said:

The sensor has been replaced that is why

So you don't mention that in the OP!

 

Phil

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 Mine will occasionally stumble off idle, it's particularly concerning when making a turn in an intersection from a stop.  A quick grab of the clutch and bump the throttle grip.  My bike runs good otherwise, PC tuned, perhaps a little rich.

When my bike was dyno'd, the paper showed a downward spike at aprx 1800.  

I've noticed that new plugs help quite a bit.  

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3 hours ago, thumper said:

2000 v11 28,000 miles will not move smoothly from stop, have to rev it up before taking off so it wont 

stumble and or die. Have done the tune up no help. Only does this when hot, if I unplug the heat

sensor it runs great. So I am thinking a possible CPU problem going to lean when hot?

Thanks in advance all ideas appreciated.

Your tune-up included valve adjustment, plugs, TPS baseline, CO Fuel Trim, and throttle body balance?

edit: and that the issue was there before the tune-up and remained unchanged?

 

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How many miles, how many years? Dirty fuel injectors always go lean, perhaps yours have made it over the margin. My bike ran fine, hand-tuned; I had the injectors cleaned, improved something like 3% on the right and 10% on the left. I had to lean the whole thing down, but the balance improvement, that is one not lean the other not rich, made it enormously smoother and fuel mileage doofing around the Spine Raid went from ~38 to 45mpg. 

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This fuel injection system on this bike is hokey-pokey compared to all other f.i. bikes. It uses a min. of inputs and a hilarious output. The pcm is mapped (apparently for Lake Como only) for nowhere on the North American continent. 

Now , for good advice , post everything going wrong with the bike and how long it has been going on . Everything you have done , all parts you have installed and has anything helped ? 

 Please read my story about plug wire caps and don't be afraid to install new spark plugs . NGK is my plug of choice on this bike .  Learn how to synch throttle bodies  and adjust TPS sensor.  If all of this is done perfectly get w/someone about "remapping" your pcm. IF you have an aftermarket module like a PowerCommander piggybacked on this bile , remove it and see what happens . Personally I hate these things. 

 If all this checks out , it's time to remove the injectors and have them professionally cleaned and flow rated to match each other. This is a job because everything is Loctited together. I suppose someone thought of this as an assembly .  Keep us posted . We want you to be happy with your bike.

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6 hours ago, thumper said:

The sensor has been replaced that is why

With electronics, there is something called "infancy failure".

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This started happening about 4 years ago just like a switch had been flipped.

1) Put a new injector assembly from ebay and a new timing chain tensioner runs the same.

2) Put a new TPS runs the same.

3) Did a full tune up after each change runs the same.

4) fresh fuel new fuel filter and all new relays and plugs runs the same.

I will keep tinkering let you guys know if I find anything just thought someone else may have had the same situation.

 

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It occurs to me to get connected to GuzziDiag and select all of the pertinent sensors to assess if their readings look "within normal limits", especially once warmed up . . .

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